Sunday, September 27, 1998 Published at 13:00 GMT 14:00 UK
Home Counties puma alert
Hertfordshire: The area where the beast is at large
A big cat has been spotted by police and members of the public in two north London suburbs, sparking a helicopter search using heat-seeking equipment.
Police have alerted residents of the area to the possible presence of the "puma-like creature" by using a loud hailer.
Search teams consisting of police and representatives from London Zoo, the RSPCA and the Royal Veterinary College have so far failed to track the animal down and will continue the search on Sunday.
"A puma is considerably larger than a Labrador. If it is a cat, it's more likely to be a lynx or some breed of African wild cat," he said.
"These animals are usually brought into the country illegally by private collectors who then lose them or release them for some reason," she told BBC News Online.
"If somebody lost it, they are unlikely to have reported it because it would lead to prosecution."
"There are problems associated with catching it live," she said.
"We have to consider the animal's welfare, but the police have to consider public safety."
The RSPCA is in consultation with a London Zoo vet about the best way to capture the creature, if and when it is found. It is thought that a sedative fired from a dart gun is the most likely solution.
'Core of truth'
"It depends on the individual, but if a big cat had escaped it only has a slim chance of survival," he said.
"Life in a cage is quite different to going out into the big bad world and hunting for yourself. In order for this creature to survive for any length of time, it would have to be part of a breeding population."
He thought that there was probably a "core of truth" to the hundreds of sightings of big cats in the UK - the most famous of which is the Beast of Bodmin Moor - but said even the police could be unreliable witnesses.
"The sightings tend to come in spells, especially if there's just been a programme on TV about it.
"I have a colleague at London Zoo who was called out last year after the police spotted a 'big cat', only to find it was an ordinary ginger moggy," he said.
The RSPCA has already been called out to deal with a number of "exotic" animals this year, including a Cayman crocodile found in Kent in August.
Other big cat sightings in the UK